Fans of Maker’s Mark whiskey have a message for the company that has brought them their favorite bourbon in trademark red-wax-sealed bottles for nearly 60 years. They’d like it neat, please. Maker’s Mark, based in Loretto, Ky., announced over the weekend that the company would begin watering down its iconic whiskey in order to boost supply. The response was lightning fast and deeply felt. A representative response on Twitter:

The addition of water will also mean the bourbon will contain almost 7% less alcohol, making it an 84-proof whiskey instead of the 90 proof it’s been bottled at since the distillery began selling its bourbon in 1959.

Alba Huerta, general manager of the nationally renowned cocktail bar Anvil in Houston, Texas, said the news left her dismayed. “I spent all day yesterday talking about this on Twitter when it exploded,” she says. “I am afraid they are diluting their brand.”

“Maker’s reputation in my bar is pretty high class. When someone walks into Anvil and don’t recognize a lot of the labels, they are likely going to turn to Maker’s. It’s always been a very approachable whiskey — but it does have character.”

The change in proof could alter that, she said, and will certainly make her less likely to use Maker’s in the craft cocktails Anvil is known for. “When you are building a cocktail, you really reach for a higher element of proof as a backbone to stand up against the dilution and other ingredients in the cocktail. A lower proof really makes a significant difference.”

In an interview with TIME, Maker’s Mark chairman emeritus Bill Samuels Jr. — whose father created the bourbon’s unique recipe in 1954 using red winter wheat instead of rye — insisted that drinkers won’t notice the difference. The idea originated with Samuels’ son, Maker’s Mark chief operating officer Rob Samuels. (The company is still family run, although it’s owned by Beam Inc., which also owns Jim Beam bourbon and Courvoisier cognac.) When Rob suggested the change last year, Bill Jr. said he was slow to agree. “Rob asked me about six months ago, ‘What would you think about a proof reduction?'” Samuels tells TIME. “I said it has to meet our taste guidelines. Our commitment is to our customers — and we really have a close relationship with them — which is why there has been so much more noise with this than with normal brands. So he had a couple bottles of the new proof made, one for me and one for him. That became our nightly cocktail.”

The elder Samuels said he drinks his Maker’s just like his own father Bill Samuels Sr. did — on the rocks or in a Manhattan. And after more than 30 days of nightly tastings, both he and his son agreed that the lower proof tasted just like Maker’s is supposed to. “I was completely convinced,” he says.

Rob adds: “The taste is the same and the process that influences the taste is exactly the same.”

That’s because the more alcohol that is in a whiskey the more your taste buds are dulled when drinking it, the elder Samuels said. Reducing the alcohol by volume means that the flavor can be more diluted and yet come across as just as strong in the drinker’s mouth and nose, according to Samuels.

Most Maker’s fans haven’t been able to put those assertions to the test yet. The new version won’t hit shelves for another two weeks or so, depending on where drinkers live, the company said.

Still, Houston’s Huerta isn’t alone among bourbon experts sweating the change. “Will Maker’s Mark sell more bourbon? Probably so,” says Joy Perrine, co-author of The Kentucky Bourbon Cocktail Book and a Louisville, Ky., bartender for nearly 40 years. “Many people won’t notice. But will it damage its standing among people who love Maker’s Mark and drink only Maker’s Mark — and there are plenty of those people? I think it will.”

Adding water to bourbon changes its profile, she said, and it’s easy enough to see why. “Do an experiment: pour yourself four shots of bourbon” adding either no water or a different amount of water in each — and see what happens. “No ice, nothing else. Give it a stir and let it sit for five or 10 minutes and taste them. Make notes. Come up with your own opinion.”

Each will taste differently, she said.

Bill Samuels Jr. has spent his entire career trying to get more people to love his father’s whiskey, and he’s built much of the company’s success bar by bar, traveling the country for his father to meet bartenders in America’s largest cities. The company sold 250 cases of whiskey in 1959; last year, it sold 1 million.

In the past, the company has been able to tinker with its aging process to keep its supply in sync with demand. “For the last 40 years, my job has been to be the guardian around this place,” he tells TIME, “and the old man was insistent that our first job, second job and third job was product consistency. He didn’t want to see any wandering around with the taste profile.” He adds, “I signed off on every batch.”

Bourbon drinking has been booming in the past decade in America and abroad, fueled in part by the craft-cocktail craze but also by the dozens of new small-batch bourbons that have come on the market in the wake of Maker’s Mark’s success. The surging demand caught even Bill Samuels Jr. by surprise — “This is the first time I’ve been this wrong,” he says — and altering the aging of the whiskey, from about seven years to just under six years, is no longer enough to keep up.

However, Rob Samuels notes that switching to a lower proof is a tweak no different to changing the aging — one that will affect the strength of the bourbon but not its taste. “And taste is what we have always gone by,” he says.

The proof, so to speak, will be in the pouring. Huerta, who is set to open a bourbon bar in Houston this year that will feature up to 150 bourbons — if they are available — said she’s worried that Maker’s, which has always been a trendsetter in the industry, is setting a dangerous precedent.

“It’s been difficult to get Maker’s for the last several months, supply has been so tight,” Huerta says. “And other distilleries are in the same position as Maker’s, without enough product to go around. But with this decision, I fear that dilution will become the solution for other distilleries too.”

“I’d rather wait six months and fight to get the whiskey I want than to put something on my shelf that is inferior.”